NSF Award
2309932
Elements are building blocks of matter that cannot be chemically interconverted. Their acquisition and utilization are essential for all life. Yet, many genes involved in the process of element acquisition are unknown. The hypothesis tested in this proposal is that genes underlying element acquisition can be detected by using their evolutionary conservation. This research uses plant genetic datasets from five diverse species (the model plant Arabidopsis, maize, sorghum, soybean, and rice) to identify genes in conserved regions of genomes that direct elemental accumulation. Mutants in these genes in Arabidopsis, maize and sorghum will be identified and characterized to determine the mechanisms of element accumulation. Comparing the results of the characterization experiments to the predictions will enable refinement of the comparative approach. The approach will also be extended to utilize data from different environments in each species permitting exploration of interactions between genes and environments in any organism. This approach is extendable to all species that can be sequenced, including other crops. Knowledge of the mechanisms of elemental homeostasis is critical to understanding plant adaptation and necessary to reduce fertilizer requirements in crops. To expand the community of scientists, we will integrate our bioinformatics and genetics research into undergraduate classrooms, bring undergraduates into the lab, conduct after-school activities for middle schoolers, and produce a podcast for scientific trainees and the research community.<br/><br/>Elemental acquisition and utilization are fundamental to metabolism in all cellular life. Plants change their metabolism and physiology to accommodate many-fold differences in element availability. Previous work used genome-wide association studies (GWAS) of elemental accumulation across five species and determined that, more often than expected, orthologous genes are present within confidence intervals of these quantitative trait loci. To validate the predictions of gene function, this project will analyze loss-of-function alleles from sequence-indexed mutant populations of Arabidopsis, sorghum, and maize for effects on elemental profiles. Among the orthologs in the GWAS experiments are genes likely involved in elemental transport and transcriptional regulators of this process. This project will explore the biology of a subset of candidate genes to determine the aspects of cell biology and gene expression they control. The project will carry out mechanistic investigations of these genes consistent with their functional annotation (e.g., transcription factor; transporter). The orthologous approach not only permits the combining of multiple GWAS experiments across species, but also can create lists of orthologs affecting environmentally contingent or population-specific variation. The project will extend the method to incorporate experiments across multiple environments and multiple population types into the orthology-based approach. This will extend the approach to permit future exploration of gene-by-environment interactions in elemental homeostasis and improve the accurate identification of causative genes from quantitative genetic experiments.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
